Automatic stoker construction for furnaces



I F. H. C. COPPUS.

AUTOMATIC STOKER CONSTRUCTION FOR FURNACES.

APPLICATION FILED FEB. e, 1918.

1,405, 1 8 Patented Jan. 31, 1922.

2 SHEETS-SHEET I.

w 9 2 9 Inveni'ov Zylfzzfovney F. H. C. COPPUS.

AUTOM'ATIC STOKER CONSTRUCTION FOR FURNACES.

APPLICATION FILED FEB. 6, 1918.

1,405, 189. Patented Jan. 31, 1922.

2 SHEETS-SHEET 2.

Elven/top 35%?ffocney TRANS H. C. COPPUS, OF WORCESTER, MASSACHUSETTS.

AUTOMATIC STOKER CONSTRUCTION FOR FURNACES.

Specification of Letters Patent.

Patented Jan. 31, 1922.

Application filed February 6, 1918. Serial No. 215,705.

7 '0 all whom it may concern:

Be it known that I, FRANS H. O. CoPrUs, a citizen of the United States, residing at Worcester, in the county of WVorcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in Automatic Stoker Constructions for F urnaces, of which the following, together with the accompanying drawings, is a specification.

The present invention relates to improvements in the construction and operation of stoking mechanisms for furnaces, where the fuel is fed continuously by mechanical means to the furnace and passes onto the grates thereof to be burned.

The invention resides in the provision of instrumentalities adapted to secure a more complete combustion of fuel than in furnaces heretofore provided with mechanical stokers of this class. Other objects and advantages of the invention are fully set forth in the accompanying detailed description of one form thereof, reference being had to the accompanying drawings, in which Figure 1 is a transverse sectional view through the combustion chamber of a furnace constructed in accordance with my invention.

Figure 2 is a top plan view thereof with the roof of the chamber removed to disclose the grates.

Figure 3 is a longitudinal sectional view of the parts shown in Figures 1 and 2.

Like reference characters refer to like parts in the different figures.

As herein shown, my invention is applied to a conventional type of furnace, having side walls 1, 1, a front wall 2, and a cover or roof 3 inclosing a combustion chamber 4. The furnace is provided with one or more stoking devices, (two being here shown) and such devices may be of well known construction. Each consists of a trough 5 in communication with a plunger cylinder 6 into which the fuel descends from a hopper 7. The fuel from hopper 7 descends in front of a plunger, not shown, in the cylinder 6, which plunger is connected by a rod 8 with a piston in a steam cylinder 9. As is usual in devices of this class, the reciprocations of the plunger in cylinder 6 force the fuel progressively into the trough 5, wherein is disposed an extension 10 of rod 8, having dogs 11 disposed at intervals thereon, to distribute the fuel equally over the whole length of the trough. As is usual in devices of this class the fuel after conipletely filling the trough 5 is, by the continuous operation of the stoker, caused to spill over the edges of said trough onto inclined grates 12, 12, where it is burned.

As in prior devices of this class, means, not shown, may be provided for pushing the burning fuel 'down the slope of each grate 12, and thence onto a horizontal support. In such prior devices, however, no provision is made for burning the fuel after it leaves the grates 12, but on the other hand said horizontal supports are constituted by dumping plates which at intervals are operated to drop the mass of residue down intothe ash pit. In the present instance, the horizontal supports which receive the fuel from the sloping grates 12, 12, take the form of perforated grates 13, 13, which are pref erablyv hinged, as at 14, from the outer ends of sloping grates 12. These grates 13'serve for the active combustion of fuel discharged thereon from the grates 12, as will be shown hereinafter, and also partake, when desired,

of the functions of the dumping plates of prior devices of the class.

The combustion-of fuel on the grates 12, 12, is supported by blast passing through the interstices of said grates, from below, in the usual manner, said blast being admitted by pipe 15 to a space or air chamber 16 beneath the stoker, which space isinclosed by side sections 17 17. Said side sections 17, 17, have extensions 18, 18 which cooperate with the sides of trough 5 to form beneath each inclined grate 12 an air passage 19, said two passages 19" being separated by a partition 20 on theunder side of trough 5. The sections 17 and their extensions 18 separate the space or chamber 16 fromthe portions 21, 21, of the ash pit which lie below the grates 13, 13, said portions or spaces 21 at'the oppositesides of the furnace being further defined by end sections 22. and at the center of the furnace by a dividing wall 23, Fig. 1. Provision is thus made for isolating the air space below the grates 12 from the portions of the ash pit underlying grates 13.

In the present construction, however, the sections 17, 17 are provided with openings 24, 24, each opening being controlled by a swinging closure 25. Said closures may be operated by rods 26, having suitable counterweights 27, or the like, to facilitate swinging of the closures to any desired position, and having means, not shown, for the retention thereof in any desired position. In one extreme position of each closure it shuts off communication'between chamber 16 and the adjacent chamber 21, as shown on the left hand Side of Fig. 1. In the other extreme position ofeach closure it fully opens its associated opening 24, and closes off, by cooperationwith the partition 20, the passage 19 of the grate 12,, as shown at the right hand side of Fig. 1. In an intermediate position, as also shown at the right hand side of Fig. 1, the closure 25 allows the blast to enter both the passage 19 and the chamber 21 and thus to support combustion on both grates 12 and 13 as illustrated in Fig.-

1, in which the pair of grates 12, 12 on the left hand side of the dividing 'wall 23 receive the entire air blast from the left hand air chamber '16, while on the right hand side of wall 23 the closures 25 cut off the air blast from the left hand grate 12 and admit the air blast to both grates 12 and 13 on the right hand side. By changing the position of the closure 25, the relative support any combustion on these dumping plates. In the present construction provision is made for completely consuming all the fuel on the grates 13 by allowing a portion of the blast to pass from chamber 16 into either of the chambers 21 or both, as conditions require. Thus all the fuel which is fed to the furnace by the stoker may be completely burned. \Vhen the fuel on the grates 13 has been fully consumed, theopenings 24 in sections 17 may be closed by the swing ing closures 25 and then the grates 13 may be dumped, the same as the dumping plates of prior devices of this class. Furthermore, by this construction, the grate area of the furnace is considerably increased, so that when unusual demands are made on the boiler the stoker can be made to feed faster;

the fuel which is not burned on grates 12 can be burned on the grates 13, with full draft to both grates, i. e., with the closures 25 in an intermediate position. Again, when the demand for steam is low the stoker may be stopped altogether, and under these conditions the closures 25 may be moved to shut off the air from passages 19, thus allowing full blast to the grates 13 to burn the fuel thereon as rapidly as possible, prior to dumping them.

The provision of the dividing wall 23 makes the two stokers entirely independent, allowing either or both of them to be operated, as may be desired. lVhen the grates of one are being cleaned, the other may be operated at a higher rate of speed than ordinarily, to offset the lower rate of combustion on the one that is being cleaned.

I claim:

1. In a furnace, a longitudinal trough for the reception of fuel, an air chamber beneath said trough, an inclined grate having its upper edge flush with the top of said trough, an air passage leading to said inclined grate from said air chamber, a grate hinged beneath the lower edge of said inclined grate, an inclosed chamber beneath. said hinged grate communicating with said air chamber independently of the passage leading to the inclined grate, and a common closure for closing either said passage to said inclined grate or the communication between said air chamber and the chamber beneath said hinged grate.

2.. In a furnace, a longitudinal trough for the reception of fuel, an air chamber beneath said trough, the walls of said air chamber having openings therethrough and having divergent portions forming with the; sides of said trough air passages, inclined grates covering said air passages, inclosed chambers on opposite sides of said air chamber and communicating therewith through said wall openings, hinged grates covering said inclosed chambers, and movable closures for closing either the air passages to said inclined grates orthe openings between said air chamber and said inclosed chambers.

3. In a furnace inclosing a. heating chamber, the combination with a pair of troughs for the reception of fuel extending through said heating chamber, a solid dividing wall between said troughs, inclined grates on opposite sides of each of said troughs, dumping grates hinged beneath the lower edges of said inclined grates, and an air chamber beneath each of said troughs, of movable members for directing air from one of said air chambers to the inclined grates adjacent to one of said troughs, and other movable members for directing air from the other of said chambers to the dumping grates adjacent to the other of said troughs, whereby the fuel on one set of grates may be consumed independently of the fuel on the other set of grates.

F BANS H. C. COPPUS.

Witnesses NELLIE W'HALEN, PENELOPE COMBERBACH. 

